Background Global wheat productivity is seriously challenged by a range of rust pathogens, especially leaf rust derived from Puccinia triticina. Since the most efficient approach to control leaf rust is genetic resistance, many efforts have been made to uncover resistance genes; however, it demands an ongoing exploration for effective resistance sources because of the advent of novel virulent races. Thus, the current study was focused on detecting leaf rust resistance-related genomic loci against the P. triticina prevalent races by GWAS in a set of Iranian cultivars and landraces. Results Evaluation of 320 Iranian bread wheat cultivars and landraces against four prevalent rust pathotypes of P. triticina (LR-99–2, LR-98–12, LR-98–22, and LR-97–12) indicated the diversity in wheat accessions responses to P. triticina. From GWAS results, 80 leaf rust resistance QTLs were located in the surrounding known QTLs/genes on almost chromosomes, except for 1D, 3D, 4D, and 7D. Of these, six MTAs (rs20781/rs20782 associated with resistance to LR-97–12; rs49543/rs52026 for LR-98–22; rs44885/rs44886 for LR-98–22/LR-98–1/LR-99–2) were found on genomic regions where no resistance genes previously reported, suggesting new loci conferring resistance to leaf rust. The GBLUP genomic prediction model appeared better than RR-BLUP and BRR, reflecting that GBLUP is a potent model for genomic selection in wheat accessions. Conclusions Overall, the newly identified MTAs as well as the highly resistant accessions in the recent work provide an opportunity towards improving leaf rust resistance.

Leaf or brown rust caused by Puccinia triticina Eriks. (Pt) is a limiting factor for wheat production. Thus, a constant search for new resistance genes or QTLs is essential to improve the resistance durability against the continued evolution of new races of Pt. This study was aimed at exploring potentially novel genes/QTLs resistance to leaf rust in Iranian wheat landraces and cultivars by using association mapping. Using a panel of 320 wheat accessions, genome-wide association study (GWAS) genotyping-by-sequencing (GBS) techniques were adopted to map loci associated with resistance to five races of Pt. A total of 17 major marker-trait associations (MTAs) were found on wheat chromosomes that were significantly linked with seedling resistance to Pt. Three markers including rs12954, rs15705, and rs42447 were detected as novel loci for resistance to PKTTS race. Our findings presented new and putative resources of leaf rust resistance in Iranian bread wheat accessions. The new identified SNPs will be valuable to expand the set of resistance genes available to control this serious disease.

To evaluate genetic diversity and to determine the relationships between yield and other importante traits among bean genotypes, an experiment was conducted in Random Completely Block Design (RCBD) with three repetitions under both normal and drought stress conditions in 2015-2016 crop season on 30 bean genotypes at Tehran University research farm. The results of variance analysis indicated high variation for the most traits. Based on means comparison, the highest and the lowest seed yield in both normal and drought conditions belonged to Daneshkadeh genotype. Regression analysis showed, under normal conditions significant relationship between sheath weight related to the number of seeds per plant, harvest index and the plant height, respectively had the highest relation with seed yields and Under stress conditions, significant relationship between sheath weight related to the number of seeds per plant, internode lenght and the day to 50% poding, respectively had the highest relation with seed yields. Factor analysis in normal and drought stress conditions, identified six factors that account for 82.7 and 85.3 percent of variations, respectively. In both conditions, the most variations were to first and second factor, the highest percent of data variation. Then the two to obtain a distribution of genotypes and identify the coordinates were used. Under normal conditions genotypes 13, 16, 12, 6, 27 and 5 and under drought stress genotypes 15, 26, 12, 18, 16 and 29 that the first and second factors were positive and above were selected as superior genotypes. Cluster analysis in both normal and drought stress conditions classified studied genotypes into four groups. The greatest diversity was observed among genotypes for traits. Thus, by selecting and breeding for traits, Increased grain yield per plant.

Leaf or brown rust caused by Puccinia triticina Eriks. (Pt) is a major biotic constraint threatening bread wheat production worldwide. The continued evolution of new races of Pt necessitates a constant search for the identification of new resistance genes, or QTLs, to enhance the resistance durability of bread varieties. On a panel of 320 bread wheat accessions, we used a genome-wide association study (GWAS) technique to map loci associated with Pt resistance using single-nucleotide polymorphism markers (SNPs) generated by genotyping-by-sequencing (GBS). The panel was tested with five Pt races gathered from different regions of IRAN to identify loci associated with seedling resistance. After estimating genetic relatedness and population structure among accessions, GWAS discovered a total of 19 SNPs on chromosomes 1B, 2B, 3A, 3B, 4A, 5B, 5D, 6A, 6B, 6D, 7B, and 7D that were significantly associated with seedling stage resistance. The three SNP markers rs12954, rs34220, and rs42447 on chromosomes 5D, 6A, and 7D, respectively, associated with resistance to Pt race PKTTS expressing potential new loci for leaf rust resistance. Overall, this research gives an integrated perspective of leaf rust resistance resources in Iranian bread wheat and recognizes new resistance loci that will be valuable to expand the set of resistance genes available to control this serious disease.

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